Process for briquetting bituminous coal



smokeless fuel results;

Patented Apr. 5, 1927.

UNITED STATES v 1,623,764 PATENT OFFICE.

SRINIVAS RAM WAGEL, OF NEW YORK, N. Y., ASSIGNOR TO THE LEHIGH COAL vAND NAVIGATION COMPANY, A CORPORATION OF PENNSYLVANIA.; I

PROCESS FOR BRIQUETTING BITUMINOUS COAL.

No Drawing. Application filed'June 16, 1924, Serial No. 720,451. Renewed July 31, 1926.

This invention relates to a process for making briquettes of bituminous coal dust, or slack, whereby a hard and substantially and it comprises more specifically a process wherein soft coal dust is mixed by steam with a sulphite binder such as is disclosed. in my copending application, Serial Number 708,571. and clay; and subsequently briquetted before finally passing the unfinished product through a series of furnaces, the passage through each furnace serving to alternately heat and cool the briquette, and the successive beatings in each furnace being at increasingly higher temperatures, as and for the purpose to be hereinafter more specifically described and claimed.

utilize bituminous coal dust as a fuel, but such attempts have not met with any material degree of success. The use of such slack as'fuel is most generally obtained by mixing it with anthracite coal, but the burning quality of the hard coal is not improved by such mixing, and the quantity which can be mixed without objectionable effects is deci'dedly limited. 7

Briquettes have also been made of bituminous coal, usually ,with an asphalt binder, but such briquettes have been found to de form under pressure and heat, and are further objectionable in that they emit a large amount of smoke in burning.

It is an object ofthe present invention to make a briquette of soft coal dust, which is capable of withstanding heat and pressure without deformation, and which is pram tically smokeless in burning.

A further object is to so harden briquettes made of soft coal that they are substantially waterproof, capable of withstanding crushing stresses, and not subject to deformation and stickiness within all the ordinary ranges of temperature.

A still further object is to make a hard and practically smokeless fuel from bituminous coal.

These objects, together with others which will be apparent as the description proceeds,

are accomplished by the following process About ninety. parts of soft coal dust, or slack, is mixed with approximately five parts of clay, and five and one-half parts of a sulphite binder such as is described in my copending application, Serial Number plished by steam.

The mass resulting from such mixing is then passed through a machine of any. conventional type for moulding it into a plurality of briquettes.

After being formed into briquettes the unfinished product is passed along a series of superposed endless conveyor belts, each of which passes through a furnace such as is shown m my copendmg application, Serial .Number 709,181. The furnace is, formed Attemptshave been made in'the past to through each tunnel consumes about four minutes.

. 1t has'also been found necessary to use a battery of such furnaces, preferably twelve to sixteen in number, so that the heating process is carried to an extent whereby, when the finished product finally emerges, it is in reality a coal brick due to the baking of the clay content therein.

The operation of the furnaces is as follows: lVhen the unfinished briquette leaves the moulding machine it is dropped onto a conveyor and slowly passed through the upper- -m ost of the vertical tier of tunnels in the action continues, each heating being higher than the previous one, and the. successive beatings being alternated by a cooling outside of the furnace, during which the temperature of the briquette drops 200 to 300 Fahrenheit. Each heating expands the briquette, and each subsequent cooling contracts it, so that as it passes through the furnace, the constituent materials are firmly knit together. f

After passing throu h the lowermost of the tunnels in the first furnace, the briquette is next passed to the uppermost tunnel of the second furnace where its travel is the same as previously. This process is carried on until the briquette. has been passed through a battery of from twelve to sixteen furnaces as has already been pointed out. During the heating of the briquette in the furnaces, it is not only hardened, but

. a large amount of the volatile matter c0ntained in the coal and binder is driven therefrom, so that the resulting product will burn with a minimum amount of smoke.

The briquette produced by the process above set forth is a coal brick, the strength of which is seven or eight times that of bituminous coal, and which possesses all of the desirable qualities of such fuel, While at the same time, those which are objectionable are eliminated.

Having described my invention, what I claim is v 1. In the manufacture of coal briquettes, the process which comprises mixing bituminous coal with cla and a binder of sulphite liquor, clay an asphalt; and in pass ing the mixture through regions of increasing temperature," with alternate cooling thereof. I

2. In the manufacture of coal briquettes, the process which comprises mixing bituminous coal with clay and a binder comosed of sulphite liquor, clay, and asphalt,

y means of steam; in alternately heating and cooling such mixture, the successive beatings being at increasingly higher temperatures.

3'. In the manufacture of coal bri uettes, the process which consists in mixing t irough the medium of steam, bituminous coal, clay, and a binder composed of sulphite liquor, clay, and asphalt; in moulding such mixture into briquettes; in passing the briquettes so formed through regions of increasing temperature; in cooling the briquettes between each successive heating; and in finally repeating the heating and cooling process.

4. In the manufacture of coal briquettes, the process which comprises mixing bituminous coal with a binder of sulphite liquor, clay and asphalt, briquetting the mixture and baking the same sufficiently to drive out a substantial amount of volatile matter quettes sufiiciently to drive out a substantial amount of volatile matter and harden the briquettes.

7. A coal briquet comprising bituminous coal and a binder of sulphite liquor, clay and asphalt which has been baked sufficiently to drive out a substantial amount of volatile matter and harden the briquettes.

8. A coal briquet comprising bituminous "coal, clay and a binder of sulphite liquor,

asphalt and clay which has been baked sufiiciently to drive out a substantial amount of volatile matter and harden the briquettes.

9. A coal briquette comprising bituminous coal and a binder of sulphite liquor, asphalt and clay which has been subjected to alter- .nate heating and cooling steps to expand and contract the same.

10. A coal briquette comprising bituminous coal, clay and a binder of sulphite liquor, clay and asphalt which has been subjected to alternate heating and cooling steps to expand and contract the same.

In testimony whereof I afiix my signature.

SRINIVAS RAM WAGEL. 

